Rod mill



july E 192.6a

v R. c. GREENFIELD ROD MILL Filed June 19, 1922 Patented July 6, 1926.

UNITED STATES PATENT oFFicE.A

ROY C. GREENFIELD, F MILWAUKEE, WISCONSIN, ASSIGNOR TO AvLLIS-CHALMERS MANUFACTURING COMPANY, OF MILWAUKEE, WISCONSIN, A CORPORATION 0F DELAWARE.

ROD MILL.

Application ined :une 19, 1922. serial No. 569,379.

This invention relates in general to improvements in comminuting apparatus, and relates more specifically to improvements in the construction and operation of rotary drum mills of the type 'wherein' material isI reduced by a plurality of elongated rodlike comminuting bodies which are free to roll and tumble about within a revolving comminuting chamber.

An object of the invention is to provide a rod mill which is simple in construction and eiiicient in operation. Another object of the invention is to provide means for eiectiiigv convenient access to the interior of'a trunnion supported rod mill, without providiir/g manholes inthe body of the mill.

It has been common commercial practice to reduce materials having certain characteristics, in rotating mills comprising a drum loaded with freely tumbling -comminuting rods. The early commercial mills of this' type were supported by means of trunnions, through one of which the material was fed into the drum and through the other of which the comminuted material was discharged. Inthese early mills, the discharge trunnion opening was ordinarily formed of suiiicient size to permit insertion of rods to the interior off the mill. but the body of the mill was provided with manholes or openings through Which the ymill liners could bev inserted. Such manholes were extremely objectionable especially in mills of this type, as it'was found impossible to provide sufiiciently tight joints between the manhole covers and the mill. to prevent leakage of. material. The use of manholes and covers therefor was also objectionable because of the inconvenience caused b vtlie removal and replacement ofthe manhole covers, and because' such constructionwas expensive 'and weakened the'sliell. v y

It was later proposed ltomodiiy the construction of rodimills by providing anopen discharge; end andl by supporting the mill upoi-ro erbe'aringscoacting with a tire at the peripheryoftliedrum adjacent to theA discharge' end-ofthe mill. While suoli open# ended'mill'construction' eliminated necessityV of rovid-` 'manholesi'n the body of Ithe mill it has roven objectionable for a number of reasons., One ofthe objections to the open-endedin-illconstruction is the fact that it requiresfconsiderably more power to oper-4 ate'a -mill having roller bearings coacting withthe periphery of the shell, than it requires to operate a trunnion supported mill wherein the bearing surfaces are relatively y near to the mill airis.l Another objection to the open-ended mill structure'is the fact that 'with su'ch a structure it is diicult to maintain a proper liquid and material discharge.,

level, it having been found that the capacity of this type of mill is increased by provid- 'ing a relatively small central discharge openling and thereby raising the liquid level. rlhe open-ended type of mill is also object-ionable since it is ditlicult with such a mill to adjust the bearings and the height of the overflow, and because of the greater cost of construction of open-ended 'mills as corn-y pared with trunnion supported` mills.

The present invention contem lates thepiovision oi a trunnion supporte rod mill in which the discharge trunnion and the discharge head liners are provided with alined openings which are of suiiicient size to permit easy entry of a man, insertion of sary for operation 'is reduced to a minimum vand the overflow level may be readily varied of iinness of the discharged material, by

Iso

to produce the desired capacity and degree` merely providing discharge trunnion liners y .l

of varying shapes and thickness. As it has been found that an opening in orden to serve as a manhole should be over 14 in diame ter, the available opening throughvthe trunnion and end head liners', should be` at leastl this amount, In order to reduce the diameter of the discharge trunnion bearing toa minimum, it is preferable that the discharge opening be of a size at mostponel-third ofthe4 diameter of the comminuting chamber. These limiting dimensions are featuresof the presentinvention.

A clear conception of several embodi.

ments of the invention and of fthe operation f' of mills constructed in accordance therewith f may be had by referring to-thefdrawing ac 'i companying and forming a part of thisv specification in whichl like reference characf ters designate the same or'similar parts in r the various views.

Y linen.

'vid'edwith a sectional'lining 8, the'sectxons' Fig. l is an elongated vertical section through an improved rod mill of the trunnion-supported type.Ik 1- Fig, 2 Ais a transverse vertical .section y through the rod mill shown in Fig. 1, lookin toward the yinlet end of the mill.'

ig. 3 is an end view 'of the rod mill lookingto'ward the discharge end of the mill.

ig. 4'is a fragmentary central vertical longitudinal section through a modified form of discharge lend head and. trunnion i The rod mill illustrated in the drawing com'rises generally a cylindricalidrum or shell) 2 having feed anddischarge end heads 3,v 4j provided Awith 'trunniens 18, 19 respecy i tively, which arecsupported, in bearings 6, 7

respectively. The trunnion 'bearings 6, 7,- arel also preferably provided Wlth adjusting means 21 for insuring proper aline` ment. ,".Th'e feed end 'head 3 is provided with forrimparting rotary motion to-the The interior of the shell?. is ro- 0L which vare preferably formed ofi several. s but fof approximately the same0 wi th andthickness. The lfeed end-head 3 se liner '11,-

preferably composed of4 sectionsfidentical .with the sections 'of thefeed end-head liner I is providedmithsectional lining Shaving a central o ning c oo rating' witha tapered inlet openie" Vforme inthe feed trunnion 'llhge' dischar end-head 4 is rovided with asectiona lining 10 whic is 9,'thereby. making the end-headA liners/inter- Achangeable. vThe discharge end-head liner.

'10 has a ycentraldischarge openingot-fi'eize approximately equal "to vthe 4discharge o'penerably loaded substantially as indica'ted with c .elongated :freelyl tumblin comminuting rods extending substantia ly v'throu r,ho`ut the, entire length of the inillzs'lhecmiil viS also. l

provided with suitable feed mechanism'fforj admitting uw, uw ,material 16 te the, mil-1i,

through the feed trunnionliner 11, 'and the 'finished lproduct 17 is `Vdischarged' through the mill discharge end opening :t as'illustratedinFig.1. .Y Theshell 2 inayalao vbe provided witlij 'a tire ljadaptedto enact/'With rollers 14.

which are adjustableI toward and a'w'ay frein the tire 13 by mea-ns of. adjusting'screwsQO. These rollers 14 are withdrawn from the tire 13 during` normal operation of/'themill and are'provlded merely yto's'erve as a temporarysuppo'rt for the discharge-end of the. mill;

-permitting adjustable rotation thereof when action ofthe liquid an surface it is found desirable to remove the discharge end-head 4 and the associated e'lements. Such removal of the end-head may b e desirable Whenjt is desired to remove the entire charge o r the entire lining from with-in the mill. The temporary roller su port may be omitted as it constitutes mere y 'a convenient assembling rig.

In-the modified form ofldischarge mechanism illustrated in Fig. 4, the mill dis- .charge end manhole opening ag is defined 'by the alinedy openings of the trunnion 1 9 and of the end-head liner 23. In this structure lthe'discharge trunnion liner 22 may be provided witlra constricted .portion 24: deber-- mining the actual discharge orifice and level.

"As' the trunnion liner 22 may be conveniently withdrawn, a mill provided with such discharge-structure possesses practically all of the advantages of the mllljillustrated ,inf

Figs. 1 to '3 inclusive., The feedend-head liners of such a mill would preferably be identical with the dischargeend-head liners 23- illustrated in Fig. 4, in ordertofprovide,

for interchangeability of the head liners.

During normal operation of the inill the' -interiorrof the mill is provided with a. char ef' or rods and of4 material substantiallyY as 1l-l 'lustra'te'ch they rods' 15 preferably lyingin lateral contactavith each other and belng ofvarious diameters. As the raw material,

1 '6 is fed Vinto the mill and ',the drum or ,shell-2' is rotated in the direction indicated,

the rods 15 cascade over the charge and imfpirrge' against the'material '1n the bottom. of the comminuting'chanfber. The material is preferably/"removed from the 'mill by the ad-j missionof Water which carries the fine mate- `ri`al 17 through the opening in the discharge Vtrunuion liner, as indicated. .By confining considerable :water in the mill with the aid ofthe'end-heads 3, 4, -the finished product 1i'v is 'freed from the ulp `by the washing quickly rises to the of the Water .and-1s discharged -with the overflow.

. Itwill be obvious thatfby in diameter and 'at'most one-third of the diameter of'the comminuting chamber', thex 'opening a: will serve' as a manholel and a roviding ami-lll end manhole opening' `vvhlc is at least 14 suitable overflow level is maintainable wth- 'mui-,11e mil-1. By providing'identical'trun nion supports :for opposite ends of.' the mill, the power consumption ma be. reduced to changeable. Theftrunm'n supporting bearings 6,' 7, nay also. be made 'of similar structure thus reducingto a minimumthe ,mills of this type:l

sired to limit the invention'to the exact details of construction and of .operation here- -1'20 almnn'num and the feed an discharge endhead1y linenstructures mayf be made nfer- 12:5v .cost ofconstruction andj4 of operation of y 'It'should be ux'lderstjood` that itl is not del we] ,if

in shown enel described, for varie-ns modifieelions wi'hin he scope or", *the claims may occur ie persons skilled in the erh le is cleiineri and desired so secure by L Letters Peienf:- Y ln combination, a rot-ery cesing and reeel, and discharge end heads enact-ing thereto forni e eonnninnting chamber, seidL seeing being free from manhole openings, e. plurality of freely tumbling rods Within end eniendingg snbstentially the entire leng'h of ssn-itl chamber, and e supporting trunnion for the mill associated with said discharge enrl heeel5 seil discharge end heed having e een?,` manhole opening through seid ,rnnni-on sn'icien, size to permiJ free rensiqer of reels therehrongh, seid opening being of less dieineer than one-lzhircl of the ismereixof seid chamber et seid henri hnv Je grenier :fourteen inches and S'zhe space nronghonr he length of the mill.

lin eoinhinetion, e rotary easing and i enel rliseherge enel heads coaotingehere 's' t ferm a comininuting ehen'iher7 snicl ons e sechionel lining `for said Chamber, a. plnrelity of freely tumbling rods within end enteneiing substantially the entiie length of seid cheinher, and e supporting trnnnion for the mill associated with Seial discharge end heechseid discharge enfl heeel having General manhole openinlr through said trunnion of snhcient size to permit free trans- "er oi seid lining `seciiions and nl sii-icl rods herei-hreugh, seid opening heini; of diere figer less ehnnlone-ifhirii el the diameter oi Wifi chamber ont greater than fourteen -f'nehes en the space in line with seid open nir unobstructed throughout the ength of the mill. v

3. 4In combination, e roery easing ferir- 'infr e coinminnting chamber, seid ces-ing hein' free from manhole openings, e plurality freely tnmhling rods within und exfeni'lsnhsteniielly he entire length of seid henri enacting she liseharge e in herring e trnnnion rele'ively smell .f lieineier secure "i erop-nie of .n ne rei-eh sei opening being unobstructedt 7 n ing being free from manhole 0penings,.

ign-ie y g eenrnlly ihereto, and ay liner for seid (lischerge encl head having e central manhole opening hrough seid trnnnion of sniicient eine lo permit free ransfer of seid ros hereshronggh, seid opening being of fliein er hen nne-hird of the diameter of szsiri chmnher hui over fourteen inches nnfl beingl free from manhole openings, a plnrniii'y ei i'reelgy uinhling rods Within and exten Eng` snhstenielly the eniire length o' said eli-einher, feed and discharge end hee-ds secured io opposite ends o"Y said casing, au snnpor'ing trnnnion connected centrally i -i each of seid heads, and interchangeable rs msoeieiecl with seid heads, each of liners having a central manhole openextenfling through said trnnnlon of an arlgeeent heed and of sufficient size to perrnil', free irzinsfer of' rods therethrough, and eneh of said openings being of diameter less than one-nhird of the dia-meter of said chamher hut over fourteen inches. and the space in line Willi said openings being unobsirneecl throughout the length of .the mili,

fr trnnnion suppored. lined menhole i'ree mill haring; en opening through one oi' ils trnnnions of size sufficient for the pes sagre oi? man,

A rirnnnion supported lined manholefree mili hfwiin;y :in opening through one of irs trnnnions of size snheieni for ehe passngre of liner seeiions.

'l'. irnnnion snpporerl line manhole `Tree inill having en unobstructed opening 'l'hrongffh iis discharge J:rnnnione' size snllrient Jfor the passage of man. i

8. A trnnnion supported lined manhole ree mill having sin unobstructed opening through ils discharge Jcrnnniofn of size suiiicient fm: 'xhe passage of liner sections.

ln resrinionjf nhereon ihe signsinre of he inventor is hereto,

fl en 

